(1) Field of the Invention
The present invention relates to thermoplastic resin compositions having excellent impact resistance, coating and adhering properties. The compositions can be widely utilized as materials for electrical and electronic parts, machine parts, automobile parts, containers, miscellaneous goods and the like.
(2) Description of the Prior Art
Propylene polymers are reasonable in price and have excellent mechanical properties, moldability, chemical resistance and the like. They are widely used in many plastic molding fields. However, in the propylene polymers the impact resistance, coating and adhering properties of molded articles therefrom are relatively poor, and for this reason, the range of use of such propylene polymers had certain limitations. On the other hand, vinyl polymers are good in coating and adhering properties, but they are poor in chemical resistance. In order to improve these poor properties of the respective resins, a method in which a polypropylene resin is blended with a vinyl polymer such as polystyrene has been proposed. Japanese Patent Unexamined Publication No. 59-217742 describes a process for improving the compatibility of the propylene polymer with the polystyrene by using a modified propylene polymer prepared by using a specific method. Japanese Patent Unexamined Publication No. 64-69651 discloses an improved process for blending the propylene polymer with the ABS resin in which a specific multi-phase structure thermoplastic resin is utilized. However, in the former case, the improvement of the compatibility of the propylene polymer with the polystyrene is not sufficient because of the insufficient graft efficiency of said modified propylene polymer.
Despite the acceptance of the improved compatibility of the propylene polymer with the ABS resin and the improved impact resistance as well as coating properties of molded articles in the latter case, the need still exists for an improved weather resistant of the composition.